Exemplary embodiments relate to a high voltage generator and, more particularly, to a high voltage generator using a negative bias.
Semiconductor memory, such as nonvolatile memory, requires a high voltage of 5 to 20 V. To this end, high voltage generators including various forms of charge pumps are being developed.
In general, the charge pumps used in the high voltage generator have limited voltage levels due to the threshold voltages of transistors. In particular, as the source voltage of the transistor is increased, the threshold voltage thereof further rises because of a body effect. Consequently, the supply voltage has to be high. In order to overcome the body effect, improved charge pumps, such as body-free charge pumps and cross-coupled charge pumps, have been developed, but they require a large number of stages for generating high voltage. Furthermore, there are concerns with the increasing area and power consumption of the charge pumps previously developed because of the additional circuitry, such as an added capacitor, utilized therein.